Are you overclocking anything? Double check and make sure all your screws on your mobo are snug and that the stands are all there as well. What else is the computer plugged in with? is it on a cheap power strip connected to 90 different extensions? Basically just fine comb everything before you just go "ah its the PSU" Oh, and what temps is your computer running at?
No overclocking, I haven't checked the snugness, I guess I can do that today, my power outlet has two plugs, one for pc and one for monitor. And all my temps read all good ( 60C GPU and everything else around 40C)